Method of forming and filling containers

ABSTRACT

A method of forming and filling containers ( 2 ) wherein a first step consists in forming a tubular body ( 3 ) of which a first end is joined to a rigid element ( 6 ) with an opening ( 7 ) capable by means of a relative closure element ( 8 ), and a second end or bottom ( 12 ) is sealed by a weld line ( 13 ) extending transversely to the axis (A) of the tubular body ( 3 ) and presents two flaps ( 15 ) extending from the lateral surface ( 4 ) of the tubular body ( 3 ), and a second step consists in flattening and sealing the flaps ( 15 ) against the bottom ( 12 ); the method also includes a step of injecting a sterilizing liquid into each container ( 2 ), effected between the first step and the second step, and a step of filling the container ( 2 ) subsequent to the sterilizing step.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Phase of International Application PCT/IB2008/002058 filed Jul. 30, 2008 which designated the U.S. and that International Application was published under PCT Article 21(2) in English.

This application claims priority to Italian Patent Application No. B02007A000548 filed Aug. 2, 2007, and PCT Application No. PCT/IB2008/002058 filed Jul. 30, 2008, which applications are incorporated by reference herein.

TECHNICAL FIELD

The present invention relates to a method of forming and filling containers, in particular containers for edible products such as milk, fruit juices, yoghurt, mineral water and the like, by way of example.

BACKGROUND ART

The containers in question are manufactured generally from a multilayer paper material and fashioned from flat diecut blanks with precreased fold lines.

The single container is of tubular construction, presenting a substantially square cross section and delimited laterally by four longitudinal walls arranged in two parallel pairs.

Containers of this type are furnished uppermost with a rigid neck of plastic material, generally threaded and closable by means of a suitable screw cap.

The bottom of the container is sealed by means of a weld line made transversely to the longitudinal axis of the container and appears as a flat wall over which two triangular flaps, coinciding with the bottom ends presented by two opposite longitudinal walls of the container, are flattened and sealed.

The containers formed in this way are transported by conveyor means to a filling machine on which they are sterilized by directing suitable cleansing substances in through the neck, and filled subsequently with one of the liquids aforementioned.

In practice however, it has been found that the method outlined above does not meet the hygiene requirements specified in quality control standards, given that there are areas in containers of this particular type to which sterilizing media cannot easily be delivered.

DISCLOSURE OF THE INVENTION

The object of the present invention is to provide a container for food products, presenting a particular structure such as will be certain to meet the hygiene requirements specified in quality control standards, and remain unaffected by the drawbacks mentioned above.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in detail, by way of example, with the aid of the accompanying drawings, in which:

FIG. 1 illustrates a machine for forming containers according to the present invention, viewed schematically in a side elevation;

FIG. 2 shows a container formed on a machine according to the present invention, viewed schematically and in perspective;

FIGS. 3 a to 3 c show a detail of the machine in FIG. 1, viewed in plan from above and illustrated in three different operating positions;

FIGS. 4 a to 4 c show a second possible embodiment of the detail in FIGS. 3 a to 3 c, viewed in plan from above and illustrated in three different operating positions;

FIG. 5 is an enlarged detail of the machine in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

With reference to FIG. 1, numeral 1 denotes a machine, in its entirety, for forming and filling containers 2.

Conventionally, the containers 2 in question are fashioned from flat blanks of multilayer paper material furnished with precreased fold lines.

As illustrated in FIG. 2, in particular, the single container 2 comprises a tubular body 3 of which the lateral surface 4 is composed of four longitudinal walls 5 arranged in two parallel pairs.

Connected to the top end of the tubular body 3 is a rigid element 6 of plastic material with an opening 7 that can be stoppered by a closure element 8.

As illustrated in FIG. 2, the rigid element 6 is furnished with a neck 9, threaded externally so as to allow the application of a closure element 8 consisting in a screw cap 10.

The rigid element 6 is provided, below the threaded portion, with an annular projection 11 of which the purpose will be explained in due course.

The bottom 12 of the container 2 is sealed by a weld line 13 transverse to the longitudinal axis A of the tubular body 3 and consists in a flat wall 14, plus two triangular flaps 15 extending from the ends presented by two mutually opposed longitudinal walls 5 of the tubular body, which are flattened against and sealed to the wall 14.

The machine 1 comprises a unit 16, of which only the outfeed portion is illustrated schematically in FIG. 1, by which the containers 2 are formed in part.

More exactly, each container 2 exits the unit 16 with the bottom 12 sealed across the aforementioned transverse weld line 13 and the triangular flaps 15 occupying the same planes as the relative longitudinal walls 5.

In short, the final operation of flattening and securing the two triangular flaps 15 to the bottom 12 is not performed by the unit denoted 16.

The containers 2, partially formed, are released from the aforementioned unit 16 at an infeed station 17 to an intermittently driven rotary conveyor 18 turning clockwise about a horizontal axis denoted B in FIG. 1.

The rotary conveyor 18 is furnished with eight angularly equispaced radial slots 19, each designed to accommodate a respective container 2 disposed with the bottom 12 facing outwards.

At an outfeed station 20 positioned 270° from the infeed station 17, the containers 2 are taken up from the rotary conveyor 18 by transfer means, denoted 21 in their entirety, and directed into a filling unit 22 that extends horizontally along a rectilinear feed path P.

The filling unit 22 consists of two continuously driven looped conveyors 23 and 24 aligned in a common plane, of which the active branches 25 and 26 are mutually opposed and extend parallel to the feed path P along the direction indicated by the arrow F.

Each conveyor 23 and 24 is equipped with a plurality of mechanisms 27 equidistant one from the next, serving to grip and support the containers 2.

Each gripping and supporting mechanism 27 comprises a gripper 28 with two jaws 29 capable of movement between an open position, and a closed position in which the neck 9 of a single container 2 is gripped at a point below the aforementioned annular projection 11.

The conveyors 23 and 24 advance at the same speed along the path of the active branches 25 and 26, whilst each gripping and supporting mechanism 27 of the one conveyor 23 advances in transverse alignment, relative to the feed path P, with a respective gripping and supporting mechanism 27 of the other conveyor 24, so that the two mechanisms form a pair 30.

Proceeding downstream in the direction of the arrow F, the filling unit 22 comprises a sterilizing assembly 31, a batching assembly 32 by which the containers 2 are filled, and a capping assembly 33.

The aforementioned transfer means 21 comprise an ejector 34, fulcrumed on a pivot 35 parallel to the horizontal axis B and capable thus of radial movement in relation to the rotary conveyor 18.

During each pause of the rotary conveyor 18, the ejector 34 removes a container 2 from the relative slot 19.

The transfer means 21 further comprise a second arm 36 fulcrumed on a pivot 37 parallel to the aforementioned axis B and capable of rocking motion in such a manner as to take up the containers 2, which are released from the conveyor 18 at an angle of 45° from the horizontal.

The second arm 36 comprises a cradle 38 designed to accommodate the containers 2, consisting in a top end wall 39 on which to rest the bottom 12 of the container, and an appendage 40 disposed at right angles to the end wall 39; the appendage 40 projects from one edge of the wall 39, offering a restraint to one longitudinal wall 5 of the container 2.

With each excursion of the second arm 36 about the relative pivot 37, moving clockwise as viewed in FIG. 1, a container 2 is taken up from the ejector 34, swung into an upright position and delivered to a transfer station 41 at the infeed of a feeder assembly 42 by which the containers 2 are routed selectively into the filling unit 22.

Referring to FIGS. 3 a, 3 b and 3 c, the feeder assembly 42 comprises an intermittently driven conveyor 43 looped around two pulleys 44 turning on vertical axes and presenting four slots 45, each equipped with means 46 by which to grip the neck 9 of a relative container 2.

With each indexing step of the conveyor 43, a container 2 is transferred by the second arm 36 to the gripping means 46 associated with a relative slot 45 of the selfsame conveyor 43.

The intermittently driven conveyor 43 transfers two containers 2 received in succession from the second arm 36, to the infeed of the one branch 25 and of the other branch 26, respectively.

The feeder assembly 42 comprises transfer means 47 consisting in a pair of grippers by which two containers 2 are taken up simultaneously from the intermittent conveyor 43 and released to a pair 30 of the aforementioned gripping and supporting mechanisms 27.

Thus, the containers 2 are formed into a succession of pairs 48 advancing along the branches 25 and 26 of the two conveyors 23 and 24.

Located beneath the branches 25 and 26 are respective belts 49 and 50 looped around two pulleys, of which the top branches 51 and 52 advance in the same direction and at the same speed as the conveyors 23 and 24.

The two belts 49 and 50 provide means on which the containers 2 are supported and guided during their passage through the filling unit 22.

The sterilizing assembly 31 is positioned above the conveyors 23 and 24 and comprises three pairs of nozzles 53 aligned on vertical axes, mounted to a support in the form of a plate 54 capable of reciprocating linear motion along the feed path P.

The nozzles 53 of each pair are aligned transversely to the feed direction of the containers 2, and capable also of vertical movement between a raised position, and a lowered position of insertion into respective containers 2 advancing along the feed path.

Each nozzle 53 is connected by way of a respective flexible pipeline to a tank 55 containing a sterilizing fluid such as hydrogen peroxide, by way of example.

The sterilizing assembly 31 comprises a valve 56 connecting the tank 55 to the nozzles 53, such as will cause the sterilizing fluid to flow into the containers 2 during the movement of the supporting plate 54 along the direction of the arrow F, when the nozzles 53 occupy their lowered operating position inserted into three successive pairs 48 of containers 2.

Downstream of the sterilizing assembly 31, the batching assembly 32 is located likewise above the conveyors 23 and 24 and comprises three pairs of nozzles 57 aligned on vertical axes, mounted to the aforementioned plate 54.

The nozzles 57 of each pair are aligned transversely to the feed direction of the containers 2, and capable also of vertical movement between a raised position, and a lowered position of insertion into respective containers 2 advancing along the feed path.

Each nozzle 57 is connected by way of a respective flexible pipeline to a tank 58 containing a liquid food product such as milk or fruit juice, or mineral water, etc. . . . .

The batching assembly 32 comprises a valve 59 connecting the tank 58 to the nozzles 57, such as will cause the liquid food product to flow into the containers 2 during the movement of the supporting plate 54 along the direction of the arrow F, when the nozzles 57 occupy their lowered operating position inserted into three successive pairs 48 of containers 2.

The capping assembly 33, which operates downstream of the batching assembly 32, comprises a device 60 associated with each branch 25 and 26 of the two conveyors 23 and 24, positioned to take up caps 10 stacked in a magazine 61, and a device 62 by which each cap 10 is screwed onto the neck 9 of a respective container 2.

The take-up device 60 and the screw-capping device 62 are mounted to a plate 63 rendered capable of reciprocating linear motion in the same way as described for the plate 54 first mentioned.

With each forward movement of the plate 63, accordingly, the containers 2 of one pair 48 will be capped simultaneously.

Also included at the filling and capping stage, associated with the active branches 25 and 26 of the conveyors 23 and 24, are guide means 64 interacting laterally with the containers 2, appearing as two belts 65 and 66 set parallel to the feed path P so as to engage two mutually opposed longitudinal walls 5 of the containers 2 during the course of the filling and capping operations.

The filling stage is followed downstream by a final station 67 comprising an assembly by which the aforementioned two triangular flaps 15 are flattened and sealed to complete the body of the container 2 as illustrated in FIG. 2.

FIGS. 4 a, 4 b and 4 c illustrate a second possible embodiment of the feeder assembly 42, where the belt-loop type intermittent conveyor 43 is replaced by a slide 68 invested with reciprocating motion in a direction transverse to the feed path P in such a way as to alternate between a first loading position and a second loading position, in which respective containers 2 are directed by the second arm 36 into two slots 69.

The slots 69 in question are of width marginally greater than the diameter of the container neck 9, and designed to support each single container 2 by way of the annular projection 11.

In the second position, once the second container 2 has been loaded into its slot, the two containers 2 are directed forward by aforementioned transfer means 47 in the manner described previously.

The containers 2 described and illustrated herein appear substantially square in section, but might equally well present a circular or polygonal section. In this instance, rather than two triangular flaps, there would be a plurality of flaps presenting an outline determined by the section of the container.

The invention affords important advantages.

Because the sterilizing step is performed on containers with the two triangular flaps not yet flattened and sealed against the bottom of the tubular body, but projecting from the mutually opposed side walls, the sterilizer fluid is effectively able to reach all internal parts of the container, thereby ensuring that the hygiene requirements specified in respect of such containers will be met in full. 

1. A method of forming and filling containers (2) including a first step wherein a blank of paper material furnished with precreased fold lines is formed into a tubular body (3), of which a first end is joined to a rigid element (6) with an opening (7) capable by a relative closure element (8), and a second end or bottom (12) is sealed by a weld line (13) extending transversely to the axis (A) of the tubular body (3) and presents at least two flaps (15) extending from the lateral surface (4) of the tubular body (3), and a second step in which the at least two flaps (15) are flattened against and sealed to the bottom (12), characterized in that it includes a step of injecting a sterilizing liquid into each container (2), effected between the first step and the second step, and a step of filling the container (2) effected subsequent to the sterilizing step.
 2. A method as in claim 1, wherein the first step of forming a blank of paper material furnished with precreased fold lines includes the step of fashioning a tubular body (3) with four longitudinal walls (5), of which a first end is joined to a rigid element (6) presenting a neck (9) closable with a suitable cap (10), and a second end or bottom (12) is sealed by a weld line (13) extending transversely to the axis (A) of the container (2) and presents two triangular flaps (15) extending from two mutually opposed longitudinal walls (5) of the container.
 3. A method as in claim 1, wherein the filling step is effected between the sterilizing step and the second flattening and sealing step.
 4. A method as in claim 1, wherein the filling step is effected after the second flattening and sealing step.
 5. A method as in claim 1, including a further step of routing the containers (2) along two rectilinear parallel branches (25, 26) of respective conveyors (23, 24) passing through a common sterilizing assembly (31) and a common filling assembly (32). 